Simmons began his professional career in 2006 when he joined the Greek League club PAOK.

He then moved to the Spanish League and ULEB Cup club Gran Canaria for the 2006–07 season, but in the middle of the season moved to Israel and signed for the Superleague club Hapoel Galil Elyon.

[7] On December 18, 2017, he returned to Israel for a third stint, signing with Hapoel Afula of the Liga Leumit for the rest of the season.

[8] One day later, he made his debut in a 94–92 win over Maccabi Hod HaSharon, recording 22 points, four assists and four rebounds.

[10] On July 25, 2023, Simmons was hired to join Kelly Graves staff as an assistant coach for the Oregon Ducks women's basketball team.